Updated: Feb 6, 2022
By Melissa Kluczynski, M.S.
Sleep is essential for good health and helps the body function normally during the day. The Centers for Disease Control and Prevention (CDC) recommends that adults get at least 7 hours of sleep each night. However, as many as 1 in 3 Americans report that they do not get the recommended amount of sleep. Not getting enough sleep is associated with many health problems, including hypertension (or high blood pressure). About 75 million Americans, or 1 in 3 adults, have hypertension.
How is Sleep Related to Blood Pressure?
Sleep helps to regulate hormones related to stress and metabolism, and not getting enough sleep can alter these hormones which can lead to hypertension and eventually heart disease and stroke. During normal sleep, blood pressure decreases by 10% to 20% (a.k.a. “blood pressure dipping”). Individuals who do not get enough sleep or who have a sleep disorder tend to have “nondipping” blood pressure (blood pressure that decreases less than 10% during sleep) which increases the risk for cardiovascular issues. A recent study by the American Heart Association (AHA) found that mild sleep disturbances including poor sleep quality, prolonged time to fall asleep, and insomnia were prevalent among adult women aged 20 to 79 years, and these sleep disturbances were associated with increased blood pressure and vascular inflammation (inflammation of the blood vessels).
Which Sleep-Related Factors Increase the Risk for Hypertension?
Obstructive sleep apnea (OSA), short sleep duration, and shift work are risk factors for hypertension. OSA occurs when the airway gets blocked repeatedly during sleep and breathing stops for short amounts of time causing snoring and gasping during sleep. OSA affects how much oxygen the body gets while asleep and can increase the risk of many health problems including hypertension, heart attack, and stroke. Risk factors for OSA include being male, non-white (Blacks, Hispanics and Native Americans are at higher risk), older age, and obesity. Among adults with hypertension, 30% to 50% have OSA. Individuals with OSA tend to have nondipping and “morning surge” (a sudden and pronounced elevation in blood pressure upon waking in the morning) in blood pressure, both of which are associated with increased risk for cardiovascular disease. Treating OSA consistently for at least 3 months with continuous positive airway pressure (CPAP) not only improves OSA symptoms but has also been shown to reduce blood pressure. However, hypertension is not necessarily caused by OSA so OSA treatment alone should not be relied upon as a way to consistently lower blood pressure. Patients with both OSA and hypertension will likely need a combination of therapies to manage both conditions. If you have hypertension and OSA, you should work with your healthcare provider to determine the best treatment plan for you.
Short sleep duration (less than 7 hours of sleep per night) on a given night is associated with high systolic blood pressure the next day. Repeated episodes of shortened sleep can lead to nondipping blood pressure. Short sleep duration combined with a sleep disorder, such as OSA, can be especially harmful for blood pressure. Among patients with OSA, short sleep duration of 5 to 6 hours or less than 5 hours increases the odds of hypertension by 45% and 80%, respectively. Shift work refers to work outside the usual hours of 9 am to 5 pm including evening or night shifts, early morning shifts, and rotating shifts. Shift work increases the risk for hypertension and is associated with cardiovascular disease morbidity and mortality.
The relationship between sleep-related factors, such as OSA, shortened sleep duration, and shift work, is complex and likely involves many factors. For instance, OSA, shortened sleep duration, and shift work are associated with weight gain, poor diet, physical inactivity, and depression/anxiety which may lead to increased risk for hypertension. The good news is that modifying one’s lifestyle (e.g., lose weight) may decrease the risk for sleep problems and hypertension.
I Occasionally have Trouble Sleeping. Do I have a Sleep Disorder?
Having trouble sleeping from time to time is normal, but if your sleep problems are not improving or if they interfere with how you feel or function during the day you should consult with your healthcare provider. Before you visit your doctor, keep a diary of your sleep habits for about 10 days and bring the diary to your appointment.
How Can I Improve My Sleep Habits?
Try adding these sleep habits to your bedtime routine:
Make your bedroom sleep-friendly by keeping it cool, quiet, and dark (remove artificial light from TV or devices)
Go to sleep and wake up at the same time every day including on weekends
Avoid caffeine, nicotine, and alcohol close to bedtime
Get regular physical activity during the daytime (at least 5 to 6 hours before bedtime)
Avoid daytime naps especially during the afternoon
Eat meals on a regular schedule and avoid late-night dinners
Limit how much fluid you drink close to bedtime to allow you to sleep longer without having to go to the bathroom
Wind down and relax before bedtime by reading a book, listening to soothing music, or taking a hot bath
Strive to get at least 7 hours of sleep each night. If you have hypertension and think you may also have a sleep disorder, such as OSA, consult with your healthcare provider to determine the best treatment plan for managing both conditions.
Melissa Kluczynski holds a Master of Science degree in Epidemiology from the University at Buffalo and she is currently working as a Research Associate in the Department of Cancer Prevention and Control at Roswell Park Comprehensive Cancer Center in Buffalo, NY. Her research interests include chronic disease prevention and women's health.
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Image source: Human Performance Resources by CHAMP https://www.hprc-online.org/mental-fitness/sleep-stress/why-you-should-prioritize-sleep-better-military-performance